The invention relates to an electrostatic powder coating installation which includes a cabin.
The electrostatic powder coating comprising a fine plastic powder which is electrostatically loaded and sprayed. By electrically grounding the object to be coated, the electrically loaded particles of powder will be deposited thereon. Within a short time the powder forms a thin, uniform coating. By subsequent heating in a furnace, the powder melts and produces a resistant coating. Although the spraying process occurs in cabins, a great part of the sprayed powder does not reach the workpiece. By means of air suction and filtering, the excess powder is recovered and delivered back to the powder delivery circuit. The powder coating installation has important advantages over wet lacquer processes, such as more efficient use of material because of powder recovery, no exhaust vapors, which is of increasing importance in regards to environmental concerns, the ability to produce a thicker layer in a single operation, shorter burning times, and a more resistant quality of the coating. On the other hand, problems arise when it is desired to change colors because all the elements participating in the spraying operation, like the powder tank, feed, spray gun, cabin suction and filter, must be changed or cleaned. In known installations such color changes have been too expensive to routinely accomplish except for large production runs.